: I was pointing out that, given that Cortana mentions both the PoA *and*
: external access junction 4C, then Foe Hammer would know that the 'crash
: site' was the PoA's, even if she hadn't been told of the plan at some
: prior point.

I found an informative link about the english language here. Read about definite articles titled "Definiteness". There is also another informative link about using thehere. Cortana's full quote is this:

"The Pillar of Autumn's engines are going critical, Foe Hammer! Request immediate extraction! Approach the crash site and be ready to pick us up at external access junction 4C as soon as you get my signal!"

Now, being that "the" is the definite article of the "crash site" there are two ways this communication could be gramatically correct: 1) this is Cortana and Foe Hammer's first communication and they understand that "the crash site" means "the Pillar of Autumn's crash site" or 2) they have had a previous conversation where Cortana had defined the crash site as the Pillar of Autumn's crash site.

You can pick between the two but the statement alone doesn't prove that Cortana was lying to Foe Hammer.